as above...i have a forge acctuator stage 3 turbo fcd and a relief valve....its wound all the way in (highest boost) and get 10psi max and the dash gauge doesnt get to the + at the end....now this car before i took it off the rd 5yrs ago ran at 14.5psi the only major difference is at the moment the aussi down pipe dcat is not fitted....(cat and standard pipe are on) as i damaged these in a crash...i have new exhaust 2 go on....but this shoudnt stop boost???

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ST185 266BHP/257FTLB

Few things you should do really:

Get rid of the FCD its not good for your engine.

Stick up a picture of how you have plumbed stuff into the actuator.

The CAT should not prevent you from making higher boost at this level.

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GT4DC Events Co-ordinator
1996 ST205 UK

1 pipe from turbo to top of actuator in that pipe i have the relif valve...the adjustment end threaded end towards the actuator... make sense??

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ST185 266BHP/257FTLB

Is it a 185 or 205 ?

Does it go straight to 10PSI at lowish RPM and hold steady, or is it very low boost until higher RPM ? Latter would indicate wastegate stuck open. Former would indicate either the relief valve stuck open where stood, or dump valve opening as pressure relief (this can happen if the vac line isn't plumbed).

As above, FCD is very bad news on a 205 as fueling is based on the pressure reading and will therefore go weak & blow engine if the boost does go above normal fuel cut level. 185 is a different matter as fueling is based on AFM.

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If at first you don't suck seed, try drier grain.

st185... it kinda boosts to 10psi then the needle drops slightly abit like it only spikes to 10 if u floor it. but if u push gentle through revs range it holds 10....really strange.... either way as i understand it with the relief valve done up it should boost high?

if actuator is stuck siezed how can u check and can it be freed up?? id of thought it wouldnt boost at all if stuck??

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ST185 266BHP/257FTLB

id say im seeing 10psi by 2900rpm 3000rpm??

quite late 2me but i had a big bhp evo before so was trying not to compare lol..and i havent driven my gt4 for 5yrs and never without the full exhaust...so i thought the lagy feel was the cat chokeing the car and low boost...but it will not boost over 10psi lol

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ST185 266BHP/257FTLB

If it's holding boost through the rev range then the actuator / wastegate part is operating correctly (I presume it's a 10psi actuator).

I'm guessing if you strip your relief valve (boost control between turbo & actuator) you'll find it's probably got damp & corroded and stuck open.

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If at first you don't suck seed, try drier grain.

iv taken apart relief valve spring ball bearing ect...its all good... i cant think why the car wont boosts higher...

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ST185 266BHP/257FTLB